The present invention relates to a wrist sphygmomanometer for measuring blood pressure by wrapping a cuff around the wrist to pressurize the wrist.
One example of conventional wrist sphygmomanometers of this type is shown in FIG. 9. A wrist sphygmomanometer 65 includes a body 70 and a cuff 80 which is integrally attached to body 70 and wrapped around the wrist. Body 70 has a display unit 71 which can stand up to display blood pressure measurements (maximum and minimum blood pressures), pulse rate and the like, and an operation unit 72 for a power ON/OFF (measurement start/stop) switch and the like. Cuff 80 contains therein a curler (not shown) for elastically maintaining cuff 80 in a substantially circular shape, and the curler is provided inside a cuff band 81 having on its surface a hook-and-loop fastener.
As shown in FIG. 10, sphygmomanometer 65 requires that cuff 80 is wrapped around the wrist of the left arm L, for example, with body 70 located on the inside (palm side) of left arm L and that the site of measurement (wrist) is matched in height with the heart (represented by the heart-shaped symbol) in order to accurately measure the blood pressure.
The conventional sphygmomanometer 65 described above requires the posture for measurement as shown in FIG. 10. Therefore, in use of sphygmomanometer 65, measurement is desirably conducted in the condition that the user sits on a chair or the like with the elbow rested on a table or the like, the measurement site (wrist) and the heart are matched in height, and the left arm is placed on an armrest such as a cushion in order to stabilize the measurement site.
However, there is a certain distance between the chest and the measurement site of the user in this posture so that it is difficult to match the height of the measurement site with that of the heart. A resultant problem is difficulty in obtaining a precise measurement of blood pressure. In addition, each time the blood pressure is measured, the height of the measurement site is likely to vary, causing an error of the blood pressure measurement due to the varying height of the measurement site and accordingly causing a problem that an accurate fluctuation of the blood pressure (blood pressure variation) is difficult to know. Another problem is that the location for measuring the blood pressure is restricted because of the need for an armrest for stabilizing the arm as well as a desk or the like on which the elbow is rested, in order to allow the user to take the posture illustrated above.
FIG. 11 shows another example of the conventional wrist sphygmomanometers. A sphygmomanometer 66 shown in FIG. 11 is similar to that shown in FIG. 9 in that the former includes a body 74 and a cuff 84 which is integrally attached to body 74 and wrapped around the wrist. Body 74 of sphygmomanometer 66 also has a display unit 76 for indicating blood pressure measurements (maximum and minimum blood pressures), pulse rate and the like and an operation unit 77 for a power ON/OFF (measurement start/stop) switch and the like.
Sphygmomanometer 66 is used by wrapping cuff 84 around the wrist of the left arm with body 74 located on the inner side (palm side) of the left arm, for example. When cuff 84 (i.e. air bag) is inflated for measurement of blood pressure, cuff 84 pressurizes the inner side of the left arm. In order to prevent the air bag from expanding outward (toward body 74), body 74 has its surface (back side) facing cuff 84, that is formed into C-shape (recessed) according to the curve of the corresponding opposite portion of cuff 84.
In order to realize a posture for measurement for allowing body 74 to be located on the inner side of the left arm, some heavy loads (mainly battery, motor, pump and the like) are arranged in sections 75a and 75b with the boundary represented by the dotted line in FIG. 11 such that the weights of the loads are balanced. Then, the fitness of sphygmomanometer 66 to the wrist is improved.
Sphygmomanometer 66 shown in FIG. 11 also requires that the measurement site (wrist) is matched with the heart in height for accurate measurement of blood pressure, and accordingly the wrist is placed lightly on the chest for measurement. This posture for measurement leads to a problem that sphygmomanometer 66 of this type cannot be reduced in size. Specifically, if the width of body 74 in the direction of extension of cuff 84 is decreased in order to avoid the side face of body 74 on the palm side from heavily pressing the chest, it would be difficult to balance the heavy loads in body 74. Further, body 74 would become unstable on the inner side of the left arm, resulting in deteriorated fitness.
Since heavy internal components are arranged within body 74 with their weights well-balanced, body 74 fitted on the wrist (the cuff has not been wrapped therearound which means that the body is just put on the wrist) sits on the wrist in a stable manner. However, when cuff 84 is being wrapped around the wrist, one end of cuff 84 is pulled so that body 74 is likely to shift from its original position on the wrist. Consequently, body 74 which was balanced is going to turn along the wrist and the weight balance is lost. When cuff 84 is actually wrapped around the wrist, body 74 could be shifted from the original desired position and attached as it is to the wrist. Therefore, the attachment is troublesome because the wrapping must be done carefully.
The present invention is made to address these problems. One object of the invention is to provide a wrist sphygmomanometer which is easier to handle.
Another object of the invention is to provide a wrist sphygmomanometer to enable an accurate blood pressure measurement and an accurate blood pressure fluctuation to be obtained without restriction on the location for measuring blood pressure.
Still another object of the invention is to provide a wrist sphygmomanometer of a smaller size which is easily attached.
In order to achieve the objects above, a wrist sphygmomanometer according to the present invention includes a body and a cuff which is integrally attached to the body and wrapped around a wrist. The body is attached to the cuff such that the body is located on thumb side of the arm when the sphygmomanometer is fitted on the wrist.
When this sphygmomanometer is fitted on the wrist with its cuff wrapped around the wrist, the body is located on the thumb side of the arm, while the conventional sphygmomanometer has its body located on the inner side (palm side) of the arm. Therefore, the sphygmomanometer of the invention allows a measurement site (wrist) to be placed on the chest for measuring blood pressure. As a result, the distance between the measurement site and the chest becomes shorter, and the height of the measurement site can easily be matched with that of the chest. Precise measurement of blood pressure is thus possible. In addition, since there are fewer instances in which the height of the measurement site varies each time blood pressure is measured, the fluctuation of blood pressure can accurately be known. Further, since the posture can be realized such that the measurement site is placed on the chest, the armrest, table on which the elbow is rested, and the like are unnecessary and thus the location for measuring blood pressure is less limited. As a result, it is possible to provide a wrist sphygmomanometer which is easier to handle and which can take an accurate blood pressure measurement as well as a precise blood pressure fluctuation without limitation on the location for measuring blood pressure.
According to another aspect of the invention, a wrist sphygmomanometer includes a body having a power supply housing portion and a cuff which is integrally attached to the body and wrapped around a wrist. The body is attached to the cuff such that the body is located on thumb side of the arm when the sphygmomanometer is fitted on the wrist. The power supply housing portion is provided to the body such that the housing portion houses power supply in the direction perpendicular to the body when the body is substantially kept horizontally.
When this sphygmomanometer is fitted on the wrist with the cuff wrapped around the wrist, the body is located on the thumb side of the arm, while the conventional sphygmomanometer has its body located on the inner side (palm side) of the arm, and accordingly the sphygmomanometer of the invention can be reduced in size. Specifically, since the body can be less protruded on the palm side (inner side), the inner side of the body never strongly presses the chest even if the measurement site (wrist) is placed on the chest. Further, since the power supply housing portion is provided to the body such that the housing portion houses the power supply in the direction vertical to the body, stability of the body is enhanced when the sphygmomanometer is fitted on the wrist and accordingly the fitness is improved.
According to still another aspect of the invention, a wrist sphygmomanometer includes a body and a cuff which is integrally attached to the body and wrapped around a wrist. The body is attached to the cuff such that the body is located on thumb side of the arm or on the outer side of the arm corresponding to back of hand. The cuff has on its palm side surface an indication-and-block member for preventing the cuff from inflating outward.
According to a further aspect of the invention, a wrist sphygmomanometer includes a body and a cuff which is connected to the body via an air flow passage member and wrapped around a wrist. The cuff has on its palm side surface an indication-and-block member for preventing the cuff from inflating outward.
When the cuff of these wrist sphygmomanometers is wrapped around the wrist, the indication-and-block member is located on the palm side surface (inner side of the arm corresponding to the palm side) to prevent the cuff from expanding outward.